1. Field of the Invention
My invention relates to machines for processing podtype vegetables and more particularly to declustering machines designed to subdivide clusters of pods prior to further processing.
2. Description of the Prior Art
When pod vegetables such as green beans are commerically harvested by machines, the pods frequently remain in clusters of two or more pods still fastened together by stem sections, and also include signle pods attached to undesirable stem sections. A necessary step in the processing of such vegetables is the subdivision of these clusters and the removal of excess stem sections so that individual pods may be further processed without waste or trash. Machines designed to subdivide such clusters are commonly referred to as declustering machines. Such a machine is described in Weirauch, U.S. Pat. No. 3,405,750.
The Weirauch machine is representative of a type of pod vegetable processing machine in which the vegetable is tumbled inside of a rotating drum. Such drums commonly comprise a multiplicity of cylindrical sections with slots penetrating their outer walls. The slots are adapted to allow the ends of pods to protrude as they tumble in the rotating drum. Knives sliding on the rotating exterior surface of the cylindrical sections cut off the protruding undesirable blossom and stem ends, a process generally referred to as "snipping". A multiplicity of such cylindrical sections are fastened end-to-end to form the drum. Partitions within the drum are adapted to maximize the likelihood that pods being processed in the drum will in fact come into contact with the outer wall of the cylindrical sections so that the ends of the pods may protrude through the slots for snipping. A passageway in each partition allows the vegetable pods being processed to migrate down the length of the rotating drum when the drum is elevated at one end.
As increasing numbers of pods are introduced into the drum, a characteristic phenomena called "roping" frequently occurs. The pods furthest from the outer edge of the drum become entwined into a relatively cohesive mass which progresses down the drum through the passages without being disturbed sufficiently to allow the individual pods to come into contact with the slots at the periphery of the drum. Attempts have been made, as in Weirauch, U.S. Pat. No. 3,405,750, to avoid roping by locating the passage in each partition so that it is not symmetrical with the central axis of the drum. Then each succeeding partition in the drum is so oriented relative to the preceding partition that the passages in them are not axially aligned. This arrangement shifts the pods in the center of the drum back and forth and tends to break up any mass of roping pods. Another effective method for dealing with roping is illustrated in the patent for a bean snipper machine issued to J. R. Urschel, U.S. Pat. No. 3,318,350. The passages in the partitions of Urschel's machine are in the form of straightsided geometric shapes with rounded corners. As the drum rotates, each straight side successively is thrust into and tends to break up any mass of roping pods.
The partitions in the Weirauch machine are further adapted to engage any clusters of pods present in the machine and thrust the stems of the clusters against rotating knives adjacent to the sides of the partitions to subdivide the clusters. To accomplish this purpose the margins of the offset, circular passages of the Weirauch partitions are serated by a series of slots into which the stems of clusters may drop and become engaged. One limitation of this design is that some clusters are so oriented that their stems pass over the slots and fail to drop into them. As a result the efficiency of the machine as a declusterer is not optimized.
There has continued to be a need in pod vegetable processing machines for a cluster-engaging surface that more efficiently engages clusters of pods so that they may be acted upon by another part of the machine. It would be an added advantage if this surface could be incorporated in a partition that efficiently discourages roping. Such a partition incorporating such a surface could then be employed in a drum of a multipurpose, pod vegetable processing machine to increase its efficiency while maintaining its simplicity of design.